The recent increase in the number of smartphones has led to a significant increase in traffic on mobile communication networks. Therefore, the off-loading of data by device-to-device (D2D) communication or the like has been studied. For example, the 3rd Generation Partnership Project (3GPP) standardization group has focused on D2D communication as a key technical area necessary for Long Term Evolution (LTE).
For example, Patent Literature 1 discloses a technique of allowing a terminal to divide transmission packets into first packets and second packets, transmit the first packets directly to a second terminal, and transmit the second packets to the second terminal via a base station.